Multi-channel mixer for a headphone control box



FIG. 1 is a front elevational view of a multi-channel mixer for a headphone control box showing our new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a left side elevational view thereof.

FIG. 5 is a right side elevational view thereof. 

The ornamental design for a multi-channel mixer for a headphone control box, as shown. 